It is proposed to establish an Animal Core to support Project 4 (Dr. Malik) and Project 5 (Dr. Kalra/. The Animal Core will develop a breeding colony of sickle transgenic mice (Tg HbS) to be used in both of these projects, and will breed immunodeficient beige/nude/xid mice for globin gene lentiviral vector biosafety testing in Project 4. The Animal Core will optimize methods for breeding, transplantation, and post-procedure maintenance of the fragile Tg HbS mice. The Animal Core will assist in development of a model for acute chest syndrome and will perform X-rays for Project 5 using the Tg HbS mice. The Animal Core will perform sequential blood and serum testing of the mice for engraftment and biosafety assays for Project 4. The Animal Core will perform organ harvest from the Tg HbS and immunodeficient mice, and will process serum and tissues, including banking, cell sorting, cryopreservation, and cryosectioning, for further detailed studies by the basic science investigators and by the Laboratory Core.